Drill bit nozzle assembly



Dec. 24, 1963 ac. MANDRELL 3,115,200

DRILL BIT NOZZLE ASSEMBLY Filed Aug. 28. 1957 2 Sheets-Sheet 1 C/a fon C. Mano re/f INVENTOR. .AWTM BY gamma/J ATTORNEVJ' 1366- 1963 c. c. MANDRELL DRILL BIT NOZZLE ASSEMBLY 2 Sheets-Sheet 2 Filed Aug. 28, 1957 C/ayzon C. Mono rev/ INVENTOR.

United States Patent Texas Filed Aug. 28, 1957, Ser. No. 680,824 Claims. (Cl. 175-340) This invention relates to improvements in nozzles and more particularly to replaceable slush nozzles for rotary drill bits.

In the drilling of wells, a mud laden fluid, generally known as slush or drilling mud, is pumped downwardly through a drill stem and is directed through slush passageways in a drill bit at the lower end of the drill stem, returning to the surface of the earth through the annular space between the drill stern and well bore. The slush may be circulated at high pressures and velocities, and may be extremely abrasive, with the result that the bore in the slush passageway in the drill bit may be subjected to heavy, and perhaps destructive wear. In order to alleviate the wear on the walls of the slush passageways, a general practice is to mount abrasion-resistant nozzles therein. Materials such as tungsten-carbide may be used in these slush nozzles to alleviate the enlargement thereof by abrasive wear; however, tungsten-carbide or the like, because of its extreme hardness, cannot be easily shaped or worked, after forming, to provide the necessary fit for leak-proof installation in the drill bit head.

One of the objects of this invention is to provide a new and improved assembly in which nozzles of various lengths may be used so that the exterior ends thereof may be positioned in accordance with the requirements of the well being drilled.

Another object is to provide a slush nozzle assembly wherein a large fluid passageway leading to the nozzle may be employed.

Another object is to provide a. slush nozzle assembly that will alleviate slush erosion of the retaining ring in the area of the nozzle discharge end.

Other objects will become apparent firom the following description and the accompanying drawings, in which:

FIG. 1 is a bottom plan view of a drill bit embodying the invention.

FIG. 2 is a fragmentary side elevation view, partly in section, of the drill bit.

FIG. 3 is an enlarged sectional view of a slush nozzle shown in operating position.

FIG. 4 is a view of the nozzle taken along the line 4-4 of FIG. 3.

FIG. 5 is an enlarged sectional view of another embodiment of the invention showing the slush nozzle in operating position.

FIG. 6 is a view of the nozzle taken along line 6-6 of FIG. 5.

In the drawings, a bit head is indicated at 1. It may be provided with the usual thread shank Z for attachment to the lower end of a drill stem (not shown). The head 1 has a plurality of bearing extensions 3 on which are rotatab-ly mounted roller cutters 4, 5, and 6, in a conventional manner.

The shank 2 of the head 1 has an opening 7 through which slush from the drill stem (not shown) passes into the chamber 8 and from the chamber into the slush passageways 1'4 and 30.

Referring to FIG. 3, it will be seen that the passageway 14 is substantially cylindrical. Within this passageway is the nozzle 9, which may be composed of tungstencarbide or any other suitable wear-resistant material. The nozzle 9 has an annular groove '11 in its periphery. A sealing ring 12 is disposed within the groove 11 to prevent fluid leakage between the nozzle 9 and the wall of Patented Dec. 24., 1953 the passageway 14. The sealing ring 12 may be com posed of a resilient material such as rubber or the like. The nozzle 9 has a locking ring groove 13 in its periphery. The wall of the passageway '14 has an annular groove 15 which may register with the groove 13 of nozzle 9. A split retaining ring 16 is disposed in and extends radially into both of the grooves 13 and 15 to hold the nozzle 9 in a predetermined position wtihin the passageway 8.

The relative radial width of the retaining ring 16 and the radim depth of one of the grooves 13 or 15 is such as to permit radial distortion of the retaining ring 16 sufiicient to disengage the ring 16 from the other of the grooves 13 or 15 to permit removal of the nozzle 9 from the passageway 14.

The nozzle 9 may be con-toured at 17 to provide access to the ends 18 of the retaining ring 16. The ends 13 of the ring 1-6 have holes 19 for the accommodation of a hand tool (not shown) to distort radially the ring 16 so that the nozzle 9 may be installed in or removed from the passageway 14.

Since the ring 16 is spaced from the lower end 2d of the nozzle '9, the ring is substantially protected from exposure to turbulent slush action exteriorly of the bit head 1, thereby alleviating slush erosion of the ring 16. The ring 16 is enclosed and covered by the bit head :1 and the nozzle 9, except for the ends 18. It the ends 18 of the ring 16 are eroded away by the slush action exteriorly of the bit head, the remaining portion of the ring 16 is adequate to retain the nozzle 9 in place within the passageway 8..

Referring to FIGS. 5 and 6, another embodiment of the invention is shown in operating position and is similar to the embodiment previously described. The slush nozzle assembly is shown generally at 21. The slush nozzle assembly 21 comprises a slush tube 24 which may be composed of tungsten carbide or other suitable wear-resistant material. An annular bushing 25 encircles the slush tube 2 4 and is secured thereto by means of brazing 26, or in any other suitable manner. The annular bushing 25 may be composed of steel or the like. The annular bushing 25 has an annular groove 27 in its periphery. A compressible sealing ring 28 is disposed within the annular groove 27. The bushing 25 has a second annular groove 29 in its periphery. The wall of the pasageway Sil has an annular groove 31 which corresponds and registers with the annular groove 29. A split retaining ring 32 is disposed within the grooves 29 and 3 1 to hold the nozzle assembly 211 in a predetermined position within the passageway 23.

The bit head 22 is contoured as at 33 to provide access to the ends 34 of the ring 32. The ring ends 34 have holes 35- fior the accommodation of a hand tool (not shown) to install or remove the nozzle assembly 21 into or out of the pasageway 30 As is clearly shown in FIG. 5, the nozzle assembly 21 may protrude from the bit head 22 at selected distances, since the groove 29 in the bushing 25 may be located closer to or farther from the lower end of the nozzle assembly 21, in accordance with the requirements of the well being drilled.

Further, since the ring 32 is the sole means of locating and retaining the nozzle assembly 21 axially in the p assageway 30, it will be apparent that the location of the nozzle assembly 21 axially within the passageway 30 is capable of being varied with a corresponding freedom from accuracy in locating the axial positions of the grooves 29 and 3'1. In other words, since the nozzle assembly is not trapped between the ring -32 and some other portion of the bit head 22 to position the same, the split ring grooves 29 and 31 respectively may be located within a wide machining tolerance and still provide a satisfactory removable slush nozzle assembly for drilling bits. Since the upper end of the nozzle assembly 21 does not seat on an annular positioning shoulder in the passage- 3 way 31?, the passageway 38 may be correspondingly larger in diameter throughout its length, thereby providing up to approximately 40% greater area of the passageway 39 adjacent the upper end of the nozzle 21; accordingly, the fluid velocity in this area is correspondingly slower, and fluid erosion of this area is reduced.

Further, since portions of the nozzle assembly 21 extend below the split ring 3 2, the ring 3 is substantially protected from slush erosion exterionly of the bit head 22. Even if the ends 34 of the ring 32 are eroded completely away by the said slush action, the remainder of the ring 32 still would be adequate to retain and position 1 re nozzle assembly 21 in the proper operating position.

It will be apparent that changes may be made in the invention without departing from the scope of the following claims.

What is claimed is:

1. A drill bit having a slush passageway, said passageway being substantially uniformly cylindrical and having in its wall between its ends a narrow annular groove, a nozzle fitting and movable in said passageway and having a narrow annular groove between its ends, and a split ring radially slidab'le in said passageway and nozzle grooves to hold said nozzle in a predetermined axial position within said passageway, a portion of the said passageway wall being contoured to pnovide access to the ends of the said split ring, axially of said passageway.

2. A drill bit having a slush passageway, said passageway being substantially uniformly cylindrical and having in its wall between its ends a narrow annular groove, a nozzle fitting and movable in said passageway and having a narrow annular groove between its ends, and a split ring radially slidable in said passageway and nozzle grooves to hold said nozzle in a predetermined axial position within said passagwray, at least one side of the said nozzle being contoured to provide access to the ends of the said split ring.

3. In a rotary drill bit, :a body member having a generally downwardly directed passageway therethrough for flushing fluid, the lower portion of said passageway being cylindrical, a replaceable nozzle member of Wear resistant material and of cylindrical shape in the lower portion of said passageway and defining therewith an interface where their cylindrical surfaces meet, said nozzle member having an outside diameter approximately equal to the inside diameter of said passageway but with sufficient clearance therebetween to permit axial sliding action without appreciable radial or wobbling movement, said nozzle member also having a flushing passageway extending axially therethrough, an annular groove in one of said members at said interface, an annular seal ring in said groove engaging the surface of the other member to prevent leakage of fluid between said members, complementary circumferential grooves in said members below said seal ring and above the uppermost of the lower ends of said members, and a zcontractable-expandable split snap ring fastener dis-posed in said complementary grooves to at least partially fill each said groove and thereby secure said nozzle member against axial movement in either direction, said fastener being retractable from either of said complementary grooves into the other by the use of a tool, at least one of said members having a portion adjacent said interface cut away axially from said complementary grooves to the lower end of the member to define an axial pocket for the insertion of such tool to retract said fastener from one of said grooves into the other whereby said nozzle may be withdrawn from said body member passageway, said axial pocket opening radially only through that axial surface of said member defining said interface.

4, The combination of claim 3 in which said fastener is retractable into said complementary groove in said nozzle member and said nozzle member contains said axial access pocket whereby said fastener may be retraded and withdrawn with said nozzle.

5. The combination of claim 3 in which said fastener is expandable into said complementary groove in said body member and said body member contains said axial access pocket.

References Cited in the file of this patent UNITED STATES PATENTS 472,342 Draudt Apr. 5, 1892 1,995,389 Howard et a1. Mar. 26, 1935 2,440,452 Smith Apr. 27, 1948 2,595,787 Heima-nn May 6, 1952 2,760,258 Rieger Aug. 28, 1956 2,805,089 Hansen Sept. 3, 1957 2,855,182 Payne Oct. 7, 1958 2,885,186 Hammer May 5, 1959 2,886,355 Wurzel May 12, 1959 FOREIGN PATENTS 570,671 Great Britain July 17, 1945 1,111,902 France Nov. 2, 1955 763,676 Great Britain Dec. 12, 1956' 

1. A DRILL BIT HAVING A SLUSH PASSAGEWAY, SAID PASSAGEWAY BEING SUBSTANTIALLY UNIFORMLY CYLINDRICAL AND HAVING IN ITS WALL BETWEEN ITS ENDS A NARROW ANNULAR GROOVE, A NOZZLE FITTING AND MOVABLE IN SAID PASSAGEWAY AND HAVING A NARROW ANNULAR GROOVE BETWEEN ITS ENDS, AND A SPLIT RING RADIALLY SLIDABLE IN SAID PASSAGEWAY AND NOZZLE GROOVES TO HOLD SAID NOZZLE IN A PREDETERMINED AXIAL POSITION WITHIN SAID PASSAGEWAY, A PORTION OF THE SAID PASSAGEWAY WALL BEING CONTOURED TO PROVIDE ACCESS TO THE ENDS OF THE SAID SPLIT RING, AXIALLY OF SAID PASSAGEWAY. 